Synthesis of functionalized tryptamines by Brønsted acid catalysed cascade reactions

An original synthetic protocol has been developed for the preparation of highly functionalized tryptamines from 2-hydroxycyclobutanone and secondary arylamines via a solvent-free Brønsted acid catalysed two-step reaction sequence

Anomalous luminescence of subglacial sediment at Haut glacier d'Arolla, Switzerland - a consequence of resetting at the glacier bed?

<p>Luminescence has the potential to elucidate glacial geomorphic processes because primary glacial sediment sources and transport pathways are associated with contrasting degrees of exposure to light. Most notably, sediment entrained from extraglacial sources should be at least partially reset, whereas sediment produced by glacial erosion of subglacial bedrock should retain substantial luminescence commensurate with a geological irradiation history.</p> <p>We set out to test the validity of this assumption at Haut Glacier d’Arolla, Switzerland using sediment sampled extraglacially and from the glacier bed. Contrary to our expectations, the subglacial samples exhibited natural signals that were substantially lower than those of other sample groups, and further (albeit limited) analyses have indicated no obvious differences in sample group luminescence characteristics or behaviour that could account for this observation. For glaciological reasons, we can eliminate both the possibility that the subglacial sediment has been extraglacially-reset or exposed in situ to heat or light. We therefore advocate investigation of possible resetting processes related to subglacial crushing and grinding, and speculate that such processes, if more generally present, may enable the dating of subglacially-deposited tills using luminescence-based techniques.</p&gt

Preserving the palaeoenvironmental record in Drylands: Bioturbation and its significance for luminescence-derived chronologies

Luminescence (OSL) dating has revolutionised the understanding of Late Pleistocene dryland activity. However, one of the key assumptions for this sort of palaeoenvironmental work is that sedimentary sequences have been preserved intact, enabling their use as proxy indicators of past changes. This relies on stabilisation or burial soon after deposition and a mechanism to prevent any subsequent re-mobilisation. As well as a dating technique OSL, especially at the single grain level, can be used to gain an insight into post-depositional processes that may distort or invalidate the palaeoenvironmental record of geological sediment sequences. This paper explores the possible impact of bioturbation (the movement of sediment by flora and fauna) on luminescence derived chronologies from Quaternary sedimentary deposits in Texas and Florida (USA) which have both independent radiocarbon chronologies and archaeological evidence. These sites clearly illustrate the ability of bioturbation to rejuvenate ancient weathered sandy bedrock and/or to alter depositional stratigraphies through the processes of exhumation and sub-surface mixing of sediment. The use of multiple OSL replicate measurements is advocated as a strategy for checking for bioturbated sediment. Where significant OSL heterogeneity is found, caution should be taken with the derived OSL ages and further measurements at the single grain level are recommended. Observations from the linear dunes of the Kalahari show them to have no bedding structure and to have OSL heterogeneity similar to that shown from the bioturbated Texan and Florida sites. The Kalahari linear dunes could have therefore undergone hitherto undetected post-depositional sediment disturbance which would have implications for the established OSL chronology for the region

Socioeconomic disadvantage but not remoteness affects short-term survival in prostate cancer: A population-based study using competing risks

© 2016 John Wiley & Sons Australia, Ltd Aim: We examined how sociodemographic, clinical and area-level factors are related to short-term prostate cancer mortality versus mortality from other causes, a crucial distinction for this disease that disproportionately affects men older than 60 years. Methods: We applied competing risk survival models to administrative data from the Queensland Cancer Registry (Australia) for men diagnosed with prostate cancer between January 2005 and July 2007, including stratification by Gleason score. Results: The men (n = 7393) in the study cohort had a median follow-up of 5 years 3 months. After adjustment, remoteness and area-level disadvantage were not significantly associated with prostate cancer mortality. However, area-level disadvantage had a significant negative relationship with hazard of death from a cause other than prostate cancer within 7 years; compared with those living in the most advantaged areas, the likelihood of mortality was higher for those in the most disadvantaged (subhazard ratio [SHR] = 1.39; 95% CI, 1.01–1.90; P = 0.041), disadvantaged (SHR = 1.51; 95% CI, 1.14–2.00; P = 0.004), middle (SHR = 1.34; 95% CI, 1.02–1.75; P = 0.034) and advantaged areas (SHR = 1.44; 95% CI, 1.09–1.89; P = 0.009). Those with Gleason score of 7 and higher had a lower hazard of prostate cancer mortality if they were living with a partner, whereas those with lower Gleason scores and living a partner had lower hazards of other-cause mortality. Conclusions: Understanding why men living in more disadvantaged areas have higher risk of non-prostate cancer mortality should be a priority

Fish oil rich diet in comparison to saturated fat rich diet offered protection against lipopolysaccharide-induced inflammation and insulin resistance in mice

<p>Abstract</p> <p>Background and Objective</p> <p>Systemic chronic inflammation is linked to metabolic syndrome, type-2 diabetes, and heart disease. Lipopolysaccharide (LPS), a Gram negative microbial product, triggers inflammation through toll-like-receptor-4 (TLR-4) signaling. It has been reported that dietary fatty acids also modulate inflammation through TLR-4. We investigated whether fish oil (FO) rich diet in comparison to saturated fat (SF) rich diet would confer protection from pathologies induced by LPS.</p> <p>Methods</p> <p>Twenty C57BL/6 mice were divided into two groups. One group received FO-diet and other received SF-diet <it>ad libitum </it>for 60 days. Diets were isocaloric containing 45% energy from fat. After 60-days of feeding, blood was collected after overnight fast. Mice were allowed to recover for 4-days, fasted for 5-hours, challenged with 100 ng/mL of LPS intraperitonially, and bled after 2-hours. After 7-days of recuperation, mice were challenged with 500 ng/mL of LPS intraperitonially and observed for physical health.</p> <p>Results</p> <p>Food intake was similar in FO- and SF-fed mice. FO-fed mice compared to SF-fed mice had significantly less body weight gain (P = 0.005), epididymal fat weight (P = 0.005), fasting blood glucose (70.8 vs 83.3 ng/dL; P < 0.05), HOMA-IR (5.0 vs 13.6; P < 0.019), and serum cholesterol (167 vs 94 mg/dL; P < 0.05). When challenged with LPS, FO-fed mice had significantly lower serum IL-1β compared to SF-fed mice (2.0 vs 30.0 pg/mL; P < 0.001). After LPS-challenge, SF-fed mice had higher mortality, lost more body weight, and had greater decrease in blood glucose compared to FO-fed mice.</p> <p>Conclusion</p> <p>Overall, FO-diet compared to SF-diet offered protection against deleterious effects of LPS in mice.</p

Loss of function mutation in toll-like receptor-4 does not offer protection against obesity and insulin resistance induced by a diet high in trans fat in mice

<p>Abstract</p> <p>Background</p> <p>Toll-like receptor-4 (TLR4) triggers inflammatory signaling in response to microbial lipoploysaccharide. It has been reported that loss of TLR4 protected against saturated fat-induced inflammation and insulin resistance. It is not known whether loss of TLR4 function offers protection against trans fat (TF) induced obesity, inflammation, and insulin resistance. We investigated whether mice with loss of function mutation in TLR4 were resistant to TF-induced pathologies such as obesity, inflammation, hyperglycemia, and hyperinsulinemia.</p> <p>Methods</p> <p>C57BL/6j and C57BL/10 mice were cross bred to generate TLR4 mutant and wild type (WT). TLR4 mutant (n = 12) and WT (n = 12) mice were fed either low fat (LF) (13.5% fat energy) or high TF diets (60% fat energy) for 12 weeks. <it>In vitro </it>experiments were conducted on mouse macrophage cells (RAW 264.7 and J774A.1) to investigate whether elaidic (trans 18:1) or oleic acid (cis 18:1) would upregulate inflammatory markers.</p> <p>Results</p> <p>TLR4 mutant mice were ~26.4% heavier than WT mice. In both genotypes, mice that received TF diet were significantly heavier than those mice that received LF diet (P < 0.01). TLR4 mutant mice compared to WT mice had significantly higher fasting blood glucose, serum insulin, insulin resistance, serum leptin, and serum cholesterol when they received TF diet (P < 0.05). No upregulation of iNOS or COX2 in response to either elaidic or oleic acid in macrophage cells was observed.</p> <p>Conclusions</p> <p>Loss of function mutation in TLR4 not only did not protect mice from TF-induced obesity, hyperglycemia, hyperinsulinemia, and hypercholesterolemia but also exacerbated the above pathologies suggesting that functional TLR4 is necessary in attenuating TF-induced deleterious effects. It is likely that TF induces pathologies through pathways independent of TLR4.</p

Preparation of Cyclobutene Acetals and Tricyclic Oxetanes through Photochemical Tandem and Cascade Reactions

We describe a photochemical reaction using two starting materials, a cyclopent-2-enone and an alkene, which are transformed in a controlled manner via the initial [2+2]-photocycloaddition adducts into cyclobutene aldehydes (conveniently trapped as stable acetals) or unprecedented angular tricyclic 4:4:4 oxetane-containing skeletons. These compounds are formed through tandem or triple cascade photochemical reaction processes, respectively. Small libraries of each compound class were prepared, thus suggesting that this photochemistry approach opens new opportunities for synthesis design and for widening molecular diversity

Scale of hospitality firms and local economic development: evidence from Crete

The hospitality industry generates benefits for many host communities including employment generation and foreign exchange earnings. However, the hospitality industry often leads to external dependency contributing to a loss of local control over resources, migrant workforce and leakages outside the local economy, seriously reducing industry's potential for generating net financial advantages and growth for the local economy. Despite the variation of size of hospitality firms, there is still limited research on how well different size hospitality firms contribute to local economic development, something which this paper addresses, taking as a case the island of Crete. The findings suggest that the smaller the size of hospitality firm the larger the benefits to the local economy

Rapid assembly of the polyhydroxylated b-amino acid constituents of microsclerodermins C, D et E.

A very short and efficient synthesis of protected derivatives of APTO and AETD, the complex polyhydroxylated -amino acid residues present in microsclerodermins C, D, and E, is described. The targets are obtained in only five steps, in 23% and 16% overall yields, respectively. The key transformation involves the completely diastereoselective two-carbon homologation of appropriately selected intermediate chiral sulfinimine

Social enterprise housing supply chains for resource-constrained communities: a complexity lens approach

Purpose: Delivering housing to resource-constrained communities is a complex process beset with difficulties. This study employs a complexity lens to examine the approach taken by a social enterprise in Australia to develop and manage a housebuilding supply chain for resource-constrained communities. Design/methodology/approach: The research team employed a longitudinal case study approach from 2017 – 2022, which utilised mixed methods to understand the phenomenon and gain an in-depth understanding of the complex issues and problem-solving undertaken by a social enterprise start-up. Findings: Balancing mission logic with commercial viability is challenging for a social enterprise. The supply chain solution that evolved accommodated the particulars of geography and the needs of many stakeholders, including the end-user community and government sponsors. Extensive and time-consuming socialisation and customisation led to a successful technical design and sustainable supply chain operation. Originality: This longitudinal case study contributes to knowledge by providing rich insights into the roles of social enterprises and how they develop and operate supply chains to fit with the needs of resource-constrained communities. Adding a contextual response dimension to an established complexity framework helped to explain how hybrid organisations balance commercial viability demands with social mission logic by amending traditional supply chain and governance practices. The case provides insights into supply chain configuration, needed changes, and potential impacts when a social enterprise as a focal actor inserts into a traditional for-profit construction supply chain. Practical implications: Analysing supply chain intricacies via a complexity framework is valuable for scholars and practitioners, assisting in designing and developing supply chain configurations and understanding their dynamics. Meeting the housing construction needs of resource-constrained communities requires the social enterprise to place societal focus at the centre of the supply chain rather than merely being a system output. The developed business model complements the engineering solution to empower a community-led housing construction supply chain.Funding and support from the New South Wales Department of Industry Tech-voucher funding scheme (Project Number 333/002/723) are gratefully acknowledged